sure. . some people dont like crushed coral because it is harder to clean and debris can build up. but if you take care of it there should be no problem.
The sand will fill the voids that would have held the debris between the crushed coral so none will accumulate.
However, if you ever siphon it, the larger grains will eventually fall to the bottom and you will be left with the finer particles on top. Which is the problem now.
I did that mix, CC on the bottem & then the sand on top, but the CC comes up in the end, it dose not look good, so dont do the CC just sand, thats what i think